Add building of devops_portal image after merge

Change-Id: Icb11c7915c15c620cc17fcad530bee05c57c45bf
diff --git a/jenkins/client/job/docker/devops-portal.yml b/jenkins/client/job/docker/devops-portal.yml
index f817568..7af37eb 100644
--- a/jenkins/client/job/docker/devops-portal.yml
+++ b/jenkins/client/job/docker/devops-portal.yml
@@ -32,6 +32,8 @@
                   - created:
                       excludeDrafts: false
                       excludeNoCodeChange: false
+                change:
+                  - merged
                 comment:
                   - addedContains:
                       commentAddedCommentContains: 'rebuild'